To meet the Agency's requirement for rapid, precise and on-site measurement of emerging contaminants such as fire retardant chemical PBDEs, critical technologies must be developed where upon mixing a reagent and a detection target, a signal is generated without the need of washing and separation steps required by existing methods. The objective of this project is to develop innovative fluorescent reagents and field- deployable devices for BDE-47 because fluorescence is among the most sensitive detection method, and BDE-47 is a wide spread congener of PBDEs. Current testing methods for PBDEs are predominantly GC/LC/MS and ELISA kits. They take multiple steps and require skilled operators, are tedious, expensive, and not suitable for field use. We plan to accomplish this objective by designing and validating several homogenous immunoassays which produce a concurrent change in fluorescence intensity in the presence of BDE-47. Specifically, we plan to identify tracer antigens for competitive format for applications that do not require high sensitivity (>ppb). For applications that require higher sensitivity (<ppb), we plan to use novel small cyclic peptides that bind to the BDE-47/antibody immunocomplex to develop sensitive sandwich assays It is within project deliverable to design and build portable fluorescence readers with easy sample collection and with wireless data capability for real-time data collection. An alternative deliverable includes rapid dipstick testing devices to be fabricated and tested for BDE-47. PUBLIC HEALTH RELEVANCE: Polybrominated diphenyl ethers (PBDEs) are common flame retardants used to reduce the risk of fire in a wide variety of products, such as mattresses, furniture, home electronics, textiles and children's toys. While they are excellent flame retardants, PBDEs enter our body through contaminated air, water and food supply. They bioaccumulate in human milk, serum and fat tissues. Scientific studies have concluded that regular exposure to even low levels of these chemicals may irreparably damage the nervous and reproductive systems, and disrupt hormones such as estrogen and thyroid hormones. In United States, PBDE concentrations in adults are 10-100 times higher than the 1-3 ppb levels found in Europe or Japan. Some studies have found concentrations of the lower-brominated PBDEs were 2- to 5-fold higher in children than in adults. Some predict PBDE body concentrations to exponentially increase doubling every 4 to 5 years. Given its wide spread use in our daily lives, effective control and elimination will be a long and challenging process. We believe that rapid and precise monitoring must be an integral part of any control program or regulation. Existing detection methods require experienced operators and take a long time, are therefore tedious, expensive, not suitable for field use. This project proposes to bridge this gap by using the state-of-the-art detection technologies to make portable devices that are field-deployable for rapid and precise measurement in humans as well as in environment.